Dr. James Hansen, who was the lead climate scientist at NASA, and sixteen other top scientists have concluded the Greenland and Antarctic glaciers will melt ten times faster than previous estimates, leading to sea level rise of ten or more feet in as little as 50 years.

In their newly released study: "Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2 ◦C global warming could be dangerous," the scientists warn that "Amplifying feedbacks in the Southern Ocean and atmosphere
contribute to dramatic climate change in our simulations."

We conclude that continued high emissions will make multi-meter sea level rise practically unavoidable and likely to occur this century. Social disruption and economic consequences of such large sea level rise could be devastating. It is not difficult to imagine that conflicts arising from forced migrations and economic collapse might make the planet ungovernable, threatening the fabric of civilization.

They are describing an ocean feedback loop near Antarctica that results in cooler freshwater from melting glaciers forcing warmer, saltier water underneath the ice sheets, speeding up the melting rate.

This would put coastal cities at significant risk of flooding, with land and property disappearing underwater altogether in some locations, and with cold air outbreaks to middle latitudes:

In the North Atlantic Ocean the increase in sea level pressure in winter slows the westerlies. Thus instead of a strong zonal wind that keeps cold polar air locked in the Arctic, there is a tendency for a less zonal flow and thus more cold air outbreaks to middle latitudes.

They go on to warn that the previous target of 2 degrees centigrade cap for Climate Change is not safe, even as we are set to blow well past that. The feedback loop, the ocean's role in regulating our climate, and its inability to keep up with changes, present a greater danger than previously anticipated, and that it cannot be easily or quickly restored:

Not only do we see evidence of changes beginning
to happen in the climate system, as discussed above, but we
have also associated these changes with amplifying feedback
processes. We understand that in a system that is out of equilibrium,
a system in which the equilibrium is difficult to restore
rapidly, a system in which major components such as
the ocean and ice sheets have great inertia but are beginning
to change, the existence of such amplifying feedbacks
presents a situation of great concern. There is a possibility, a
real danger, that we will hand young people and future generations
a climate system that is practically out of their control.

Dr. Michael Mann of Penn State testified before the Democratic Platform Drafting Committee about the critical issue of climate change, and the importance of building on the progress from the Paris Climate Conference.

Opening Statement transcript:

"Thank you, Congressman, and community members. I am honored to speak to you about this critical issue. My name is Michael Mann. I'm a distinguished professor of atmospheric science at Penn State. I spend my time teaching, advising students, during scientific research. Fundamentally, I am a climate scientist and I have spent much of my year with my head buried in climate data trying to seize out the signal of human caused climate change.

What is disconcerting to me and so many colleagues are these tools we have spent years developing, increasingly, are unnecessary because we can see climate change, the impact of climate change now playing out in real-time on our television screens. The impacts -- b food, water, health, national security, our economy -- climate change is creating -- taking a great toll. We've seen that in floods. The floods we have seen over the past year in Texas and in South Carolina. We see it in the devastating combination of sea level rise and more just active hurricanes -- destructive hurricanes which has led to calamities like superstorm sandy and what is now the perennial flooding of Miami beach. We see it in unprecedented drought, like that which continues to afflict California, doubling the area of wildfire, fire burning in the western U.S., and indeed, in the record heat we may see this weekend in phoenix, Arizona.

The signal of climate change is no longer subtle. It is obvious. And like the tip of the proverbial iceberg, further changes like the melting of the ice sheet to give us three feet of c rise by the end of the century, may be locked and simply from the carbon we have burned, from the warming in the pipeline due to the burning of fossil fuels. There are some tipping points. There are some we may not have crossed and can still avoid. It is still possible to avert catastrophic and potentially. Reversible changes in climate, but only by moving forward, building on the progress, and accelerating the transition away from fossil fuels towards a clean energy economy.

The stakes could not be greater. The future of our children and grandchildren literally hangs in the balance. No contrast could be more stark. We have the republican party whose standard bearer and a vast majority of their congressional representatives continue to deny that climate change exists. We have a democratic party that realizes that while we can debate the specifics of the worsening crisis, we cannot bury our heads in the sand and ignore the growing threat.

It is my hope that the Democratic Party will have a statement about putting a price on carbon -- it is my hope that the platform will it knowledge of the Obama Administration and promised to build on that legacy by defending the clean power plan against attacks by congressional republicans and by ensuring other EPA policies to reduce carbon emissions are kept in place. It is my hope the platform will acknowledge that we should hold on."